A touch sensing substrate includes a substrate, a first light sensing element, a second light sensing element and a first bias line. The first light sensing element includes a first gate electrode, a first active pattern overlapping with the first gate electrode, a first source electrode partially overlapping with the first active pattern and a first drain electrode partially overlapping with the first active pattern. The second light sensing element includes a second gate electrode, a second active pattern overlapping with the second gate electrode, a second source electrode partially overlapping with the second active pattern and a second drain electrode partially overlapping with the second active pattern. The first bias line is connected to the first and second gate electrodes.